1. Field of the Invention
The present invention relates to a means and method of analyzing naturally occurring and artificially produced biological fluids. More particularly, the present invention concerns a means and method of reducing turbidity in various biological samples for other biological assays, for example hemoglobin determination, whole blood, glucose, neonatal bilirubin, cholesterol and/or triglycerides in blood serum or plasma.
2. Prior Art
Many assays of biological fluids such as glucose, albumin, etc., in whole blood or plasma, require colorimetric methods of analysis. In such samples, elevated triglyceride levels interfere with accurate determinations by causing sample turbidity which poses prblems during analysis.
Blood assays to determine total blood hemoglobin are a necessary element of medical blood work-ups. To ascertain hemoglobin content of blood, hemoglobin is conventionally converted to cyanomethemoglobin using Drabkin's reagent. However, the presence of elevated levels of triglycerides in both whole blood and plasma samples causes turbidity during conventional analysis. The turbidity created by the triglycerides in the samples creates difficulties in determining the hemoglobin content of the sample. Turbidity has deleterious effects on measurements requiring optical analysis and in radioimmunoassays.
To overcome problems of turbidity many means and methods have been developed. Presently, the predominant approaches are ultracentrifugation, organic solvent extraction or chemical precipitation of the lipoproteins. These are time-consuming, arduous and cumbersome techniques.
Exemplifying the prior art is, for example, U.S. Pat. No. 4,309,502. This patent teaches a reagent kit for the hydrolysis of triglycerides to glycerol a nd free fatty acids using lipase, and at least one reagent capable of assaying glycerol. The invention disclosed in this reference is predicated on the use of a microbial source of lipase such as Chromobacterium viscosum, which, in turn, requires activation by the presence of a surfactant.
Other relevant art is found in U.S. Pat. Nos. 4,338,395; 3,168,448; 3,759,793; 4,245,041; 3,703,591; 4,012,287 and 3,853,465.
In McGowan et al, Clinical Chemistry, vol. 29, No. 3, 1983, there is described a totally enzymatic technique for measuring triglycerides involving the complexation of generated fatty acids thus eliminating the production of turbidity.
None of the prior art is directd to the elimination of triglycerides to reduce the rurbidity generated thereby. It is to be appreciated that the prior art fails to provide a simple, one-step reagent which overcomes the turbidity in samples of biological fluids to permit sample assaying. It is to this purpose that the present invention is directed.